Appliance for bubbling compressed air through a liquid, particularly water in a bathing tub and the like

ABSTRACT

An appliance for bubbling compressed air through a liquid, particularly water in a bathing tub and the like, comprises compressed-air generating means such as a blower, compressor and the like for blowing compressed air into a controllable air bubble generating mat immersed in the liquid through an air hose incorporating means for preventing liquid from flowing back into the compressed-air generating means. The appliance is characterized by the combination of the following features: I. THE COMPRESSED-AIR GENERATING MEANS ARE CONTAINED IN A SYNTHETIC PLASTICS CASING WHICH COMPLETELY ENCLOSES THE SAME, CONTAINS CONTROL MEANS AND HAS AN OPENING CLOSABLE BY A PREFERABLY HINGED INSULATING COVER; II. THE AIR HOSE LEADS FROM THE COMPRESSED-AIR GENERATING MEANS IN THE SYNTHETIC PLASTICS CASING TO AN AIR DISTRIBUTOR HEAD OF THE AIR BUBBLE GENERATING MAT AND COMPRISES TWO SEPARATE LENGTHS OF HOSE JOINED TOGETHER BY A HORIZONTALLY OR VERTICALLY LOCATED CONNECTOR, PREFERABLY AN ANGULAR CONNECTOR, WHICH IS AIRTIGHT ONLY WHEN LOCATED AT A GIVEN LEVEL ABOVE THE AIR BUBBLE GENERATING MAT, III. THE AIR BUBBLE GENERATING MAT COMPRISES SEVERAL LONGITUDINALLY JOINED CATERPILLAR-LIKE ELEMENTS AND IS TRAVERSED IN ITS LENGTHWISE DIRECTION BY A PLURALITY OF PERFORATED AIR TUBES CONNECTED TO THE AIR DISTRIBUTOR HEAD WHICH PERMITS COMPRESSED AIR PERMANENTLY TO BE SELECTABLY ADMITTED INTO SAID PERFORATED AIR TUBES.

United States Patent mi Baumann ["111 3,809,073 [451 May 7,1974

[22] Filed: Mar. 27, 1973 [21] Appl. No.: 345,423

[30] Foreign Application Priority Data June 20, 1972 Germany... 2229973 [52] US. CL; 128/66 [51] Int. Cl A6111 9/00 [58] Field of Search 128/66; 4/178, 180

[56] References Cited UNITED STATES PATENTS 3,417,747 12/1968 Beger .i 128/66 3,710,786 1/1973 Rico 6t 31. .,.L 128/66 FOREIGN PATENTS OR APPLICATIONS France 4/180 Primary Exarriiner-Lawrence W. Trapp Attorney, Agent, or Firm -Markva & Smith [57] ABSTRACT An appliance for bubbling compressed air through a liquid, particularly water in a bathing tub and the like,

, comprises compressed-air generatingmeans such as'a back intothe compressed-air generating means; The

appliance is characterized by the combination of the following features:

i. the compressed-air generating means are contained in a synthetic plastics casing which completely encloses the same, contains control means and has an opening closable by a preferably hinged insulating cover;

ii. the air hose leads from the compressed-air generating means in the synthetic plastics casing to an air distributor head of the air bubble generating mat and comprises two separate lengths of hose joinedtogether by a horizontally or vertically located connector, preferably an angular connector, which is airtight only when located at a givenlevel above the air bubble generating mat,

iii. the air bubble generating mat comprises several longitudinally joined caterpillar-like elements and is traversed in its lengthwise direction by a pluralityof perforated air tubes connected to the air distributor head which permits compressed air permanently to be selectably admitted into said perforated air tubes.

11 Claims, SDrawing-Figures PATENTEDMAY 7 m4 SHEET 2 OF 2 FIG. 3

FIGS

THROUGH A LIQUID, PARTICULARLY WATER IN A BATHING TUB AND THE LIKE BACKGROUND OF THE INVENTION This invention relates to an appliance for bubbling compressed air through a liquid, particularly water in a bathing tuband the like, comprising compressed-air generating means such as a blower, compressor and the like for blowing the compressed air into a controllable air bubble generating mat immersed in the liquid through an air hose incorporating means for preventing flow of the water from the bath tub back into the compressed-air generating means. The contemplated appliance is an improvement with respect to form, disposition and general design of arrangements of this kind already known in the art.

The employment of electrically driven appliances in bathrooms is certainly hazardous if the user fails to ob serve the operating instructions laid down by the manufacturers of the appliances. In prior art bubble bathappliances the necessary precautions have undoubtedly been taken to eliminate the hazard of electric shock,

always provided the operating conditions are in fact exactly observed.

Nevertheless, in practice it is a not infrequent occurrence that as the matter of convenience or as a result of sheer carelessness operating instructions are simply ignored and that bathers operate the main switch of the compressed-air generating means when they are still wet from the bath. Occasionally they also omit to raise the center of the air hose connecting the compressed air generating means to the air bubble generating mat in the bath tub to the prescribed height and it is therefore possible when the mat is taken out of the bath tub for water to flow from the mat through the air hose into the compressed-air generating means.

SUMMARY OF THE INVENTION In order to eliminate these shortcomings of the known appliances and to protect the bather by the provision of foolproof precautions it is an object of the present inventionto provide an appliance for bubbling compressed air through a liquid, particularly water in a bath tub and the like, in which it is impossible to carry out control operations whilst the electrical circuit is live and the middle part of the air hose connecting the compressed-air generating means to the mat in the bath tub must be raised before the appliance will work.

Another object of the invention is to provide the mat with means which facilitate control of the mat in the bath tub, thereby discouraging neglect exclusively for the sake of convenience.

To attain these objects the present invention provides an appliance for bubbling compressed air through a liquid, particularly water in a bathing tub-and the like, which comprises compressed-air generating means such as a blower, compressor and the like for blowing compressed air into a controllable air bubble generating mat immersed in the liquid through an air hose incorporating means for preventing liquid from flowing back into the compressed-air generating means, said appliance being characterized by the combination of.

the following features:

i. the compressed-air generating means are contained in a synthetic plastics casing which completely encloses the same, contains control means and has an 2 opening closableby a preferably hinged insulating cover;

ii. the air hose leads from the compressed-air generating means in'the synthetic plastics casing to an air distributor head of the air bubble generating mat and comprises two separate lengths of hose joined together by a horizontally or verticallylocated connector, preferably an angular connector, which is airtight only when located at a given level above the air bubble generating mat, preferably at a height equalling that of a man, and

iii. the air bubble generating mat comprises several longitudinally joined caterpillar-like elements and is traversed in its lengthwise direction by a plurality of perforated air tubes connected to the air distrib' utor head which permits compressed air permanently to beselectably admitted into said perforated air tubes. The control means contained in the synthetic plastics casing preferably comprise an electric time switch, an electronic speed regulator or a speed selector switch,

a warning lamp and an electrical push button on-off switch for the compressed-air generating means which are all mounted on a common control panel in the plastics casing accommodating the compressed-air generating meansin such a way thatthe push button of the onoff switch is located in the path of deflection of the insulating cover hingeably attached for instance by means of a pianohinge to the edge of the opening, which is nearest to the air hose length, said opening giving access to said control panel. By this arrangement it is ensured that the compressed-air generating means cannot be energized until the insulating cover firmly covers the entire control panel. A bather cannot therefore touch the control means from the bath tub without first opening the insulating cover and thereby switching off the electric current.

Moreover, the user of such an air'bubble bath appliance is always forced to raise the center part of the air hose to substantially the height of a man because a supply of compressed air cannot otherwise reach the air bubble generating mat. For example, should the user leave the air hose lying on the floor, avalve provided in the connector joining the two lengths of air hose will be open forexhausting the air which cannot therefore reach the air bubble generating mat. Only when the connector which is preferably of angular construction is arranged on a level substantially corresponding to the height of a man the valve is closed and the air can pass therethrou'gh. Moreover, as soon as the user, after having taken his bath, attempts to lift the air bubble generating mat out of the bath tube, he will cause the connector to tip up and to open the valve for discharging water that may drain into the air hose. The connector for joining the two lengths of air hose may alternatively be straight and likewise divided into two'halves substantially in the middle, said halves being connected together by a hinge and their cooperating edges having sealing profiles which form a sealing joint when the connector is in position for the passage therethrough of air from the compressed-air generating means. When in this form of construction the mat is lifted out of the bath tub the halves of the tubular connector hingeably which selectably admits the air from the compressedair generating means into the air tubes of the said mat in such a way that despite the disconnection of some 'of the air tubes the remaining air tubes will still provide the same cross section of flow as the air hose. The motor of the compressed-air generating means cannot therefore be operatively impeded by lack of circulation and a consequent temperature rise. In this context it is particularly advantageous to provide the upper surface of the mat on which the bathers body rests with transverse grooves or flut'ings to provide a path of escape for the air from the compressed-air generating means when the outlet openings of the air tubes are obstructed by the adipose tissue of particularly stout users.

BRIEF DESCRIPTION OF THE DRAWINGS Two embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which:

FIG. 1 is a general view of an air bubbling appliance according to the invention;

FIG. 2 is a top plan view of an air bubble generating mat and a longitudinal section of an air distributor head attached thereto and composed of two telescoped tubes of which the inner tube can be rotated in relation to the outer tube and serves for controlling the admission of compressed air into the air bubble generating mat;

FIG. 3 is a view similar to that shown in FIG. 2 but showing the air bubble generating mat filled with a modified air distributor head;

FIG. 4 is a section of an angular connector and valve for joining the air hose length from the compressed-air generating means to the air hose length to the air distributor head, and 7 FIG. 5 is a front elevational view of the synthetic plastics casing accommodating the compressed-air generating means and a control panel mounted behind a preferably hinged cover.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. I shows an appliance for bubbling a compressed gas, such ascompressed air, through a liquid, particularly water in a bathing tub and the like, which comprises a compressed-air generating means such as a blower, compressor and the like mounted inside a synthetic plastics casing l for delivering compressed air into one end of a length of air hose 2 which at its other end is connected to a preferably angular connector '4. From this connector 4 a further length of air hose 5 leads to an air distributor head 6 attached to an air bubble generating mat 7 placed on the bottom of a bath tub 80.

It will be understood by reference to FIG. 5 that control means comprising for instance an electric time switch 30, an electronic speed regulator or a speed selector switch 32, a warning lamp 31, and an electrical push button on-off switch 33 operating the main switch for the compressed-air generating means are mounted on a control panel 41 inside the plastics casing l. A correspondingly shaped opening in the plastics casing 1 gives access to said control panel. A flap or cover 34 made of insulating material is hinged to the edge of the opening which is nearest to the length of air hose 2 by means of a piano hinge 35 and adapted when closed to cover the control panel 41 and its control means. The

push button on-off switch'33 is located in the closing part of the hinged cover 34 in such a manner that the on-off switch 33 remains off until the cover is fully closed. The other control means cannot be set whilst the main switch is on.

As illustrated in FIG. 4 the connector 4 between the length of air hose 2 from the compressed-air generating means and the length of air hose 5 to the air distributor head 6 of the air bubble generating mat 7 is of angular construction and mounted on a pivot pin 36 on a wall fitting 3. The portion of the connector 4 to which the length of air hose 5 is connected contains an orifice 40. When the air bubble generating mat 7 is in operation a taper pin 39 attached to the wall fitting 3 enters the orifice 40 and thus seals it. When the bath tub 80 is to be cleaned, the air hose length 5 is lifted and the mat 7 is taken out of the bath tub 80 and hung onto a hook 38 on the wall fitting 3, the angular connector 4 tilting upwards as indicated by an arrow in FIG. 4. The taper pin 39 ceases to project into the orifice 40 in the connector 4 and consequently water draining from the mat 7 can be discharged through the orifice 40 in the connector 4 without reaching the compressed-air generating means. The same effect could be achieved (not shown in the drawings) if the connector 4 between the ends of the two air hose lengths 2 and 5 were straight but divided in the middle into the halves connected by a hinge, the edges of the two halves in the straight closed position of the connector 4 forming a sealing joint. Lifting of the mat 7 results in the two halves hingeably opening and thus allowing water draining from the mat 7 to be discharged through the orifice 40.

The portion of the connector 4 containing the orifice 40 may form an enlargement containing a light-weight ball-shaped float 37 adapted in the event of water entering from air hose length 5 to close the part of the connector 4 to which the end of the air hose length 2 is attached (cf. FIG. 4).

Referring to FIGS. 2 and 3 it will be seen that the air bubble generating mat 7 may consist of flexible caterpillar-like sections traversed in the illustrated embodiment by five perforated air tubes 8 and 9, the air tube 9 in the center having a larger diameter as well as larger holes 11 than the others, the two pairs of tubes 8 on each side being of smaller diameter and having smaller holes 10. The air distributor head 6 which admits air into these perforated air tubes 8 and 9 permits air to be selectably dischargedfrom specific perforated tubes in such a manner that the entire air delivered by the compressed-air generating means can issue without a build up of static pressure.

Moreover, the generation of static back pressure due to some of the holes of the tubes being blocked by the flabby skin of corpulent persons is avoided by the provision of transverse grooves which traverse the upper surface of the mat 7 and thus provide paths of escape for the air (not shown in the drawings).

The air distributor head 6 spans the width of the mat 7 and as illustrated may contain five connections for the perforated air tubes of the mat 7, besides'having a further connection at one end for the air hose length 5.

In the arrangement illustrated in FIG. 2 the air distributor head 6 consists of a tube which is closed at both ends and which in its interior contains a further tube 14 which makes an airtight sliding seal and can be rotated by a knob 18 at one end. The inner tube 14 contains four openings or ports along its length. When the inner tube 14 is in the position illustrated in FIG. 2 these ports 15 exactly register with connections 12 and the air tubes 8 in the mat 7 so that air from the compressed-air generating means entering through the air hose length 5 is admitted into these perforated air tubes 8 in the mat 7. When the inner tube 14 is rotated by the knob 18 through the angle of 180 ports 16 and 17 are brought into register with a connection 13 on the larger diameter central air tube 9 and the neighbouring connections 12 of the two air tubes 8 on either side. It is therefore possible to expose the entire body of the bather to the bubble action or, alternatively, intensely to treat only the spinal part of the back.

Another embodiment of the air distributor head 6 is illustrated in FIG. 3. In this case the air distributor head 6 consists of a bank of three pipes 19, 20, and 21 which at each of their ends are closed by a cap 25 and 26 common to them all. One of these caps, namely cap 26, is provided with a connectingfitting for the air hose length 5 from the connector 4. Thiscap 26 also contains a rotary disc valve 27'which is operable by a knob 29 on the outside for selectably giving access through an opening 28 in the rotary disc valve 27 to the pipes 19, and/or 21. The upper pipe 19 communicates via a connection 24 with the central perforated tube 9 of the mat 7, whereas the pipe 20 through a connection 23 communicates with the two neighbouring perforated air tubes 8 and the pipe 21 through a connection 22 with the two outer perforated air tubes 8 in the air bubble generating mat 7.

When the rotary disc valve 27 is in the position illustrated in FIG. 3 the air from the compressed-air generating means delivered through the air hose length 5 is admitted on the one hand through the pipe 20 and the connection 23 to the two perforated air tubes 8 on each side of the central perforated air tube 9 andon the other hand through the pipe 21 through connections 22 into the two outer perforated air tubes 8. When the rotary disc valve 27 is rotated I80? pipe 21 is cut off and the air is admitted on the one hand into the pipe 19 and through connection 24 to the perforated largerdiameter tube 9 in the center of the mat 7 and on the other handinto the pipe 20 and through connection 23 into the two perforated air tubes 8 directly next to the central perforated air tube 9 in the air bubble generating mat 7. 1

Without in any way affecting the air distributing function the caps 25 and 26 closing the ends of the air distributor head 6 are interchangeable so that the air hose length 5 can be attached to the right or left hand end of the air distributorhead 6 according to the position of the bath tub in the bathroom.

The number of perforated tubes contained in the air bubble generating mat 7 is discretionary. For instance, on both longitudinal edges of the air bubble generating mat 7 two additional perforated air tubes might be provided having holes pointing downwards or at least being situated below the plane containing the holes of the other air tubes. Control may again be effected by means of the air distributor head 6. The purpose of such an arrangement is to permit a foam bath for particular therapeutic effects to be produced by adding a foaming agent to a very small amount of water which would not as such be sufiicient for adequately covering the air bubble generating mat 7.

It will be readily understood that the illustrated embodiments can be modified in many respects to suit any particular set of conditions. For example, the compressed-air generating means could be located inside a cabinet, in a niche in the wall or in some similar position in which the closing of a cover or flap is necessary for starting the compressed-air generating means.

What is claimed is: I

1. An appliance for bubbling compressed air through a liquid, particularly water in a bathing tub and the like, comprising compressed-air generating means for blowing compressed air into a controllable air bubble genen ating mat immersed in the liquid through an air hose incorporating means for preventing liquid from flowing back into the compressed air generating means, said appliance being characterized by the combination of the following features:

i. the compressed-air generating means are, contained Y in a synthetic plastics casing which completely encloses the same, contains control means and has an opening closable by a hinged insulating cover;

ii. the air hose leads from the compressed-air gener ating means in the synthetic plastics casin g to an air distributor head of the air bubble generating mat and comprises two separate lengths of hose joined together by a connector which is airtight only when located at a given level above the air bubble generating mat, and

iii. the airbubble generating mat comprises several longitudinally joined caterpillar-like elements and is traversed in its lengthwise direction by a plurality of perforated air tubes connected to the air distributor head which permits compressed air permanently to be selectably admitted into said perforated air tubes.

2. An appliance according to claim 1, wherein the control means contained in the synthetic plastics casing comprise an electric time switch, an electronic speed regulator or a speed selector switch, a warning lamp and an electrical push button on-off switch for the compressed air generating means which are all mounted on ,a common control panel in the plastics casing accommodating the compressed-air generating means in such a way that the push button'on the on-off switch is located in the path of deflection of the insulating cover hingeably attachedto the edge of the opening, which is nearest tothe air hose, said opening given access to said control panel.

3. An appliance according to claim 1, wherein the connector for joining together the free ends of the air hose length from the compressed-air generating means in the plastics casing and of the air hose length to the air distributorhead of the air bubble generating mat is deflectably mounted on a pivot pin on a wall fitting, the portion of said connector cooperating with the air hose length to the air distributor head containing an orifice which during operation of the appliance is sealed by the entry into said orifice of a taper pin attached to the wall fitting.

4. An appliance according to claim 3, wherein the connector has an enlargement in the regionof said orifree and inside said enlargement contains a light-weight ball-shaped float which closes the end of the air hose length from the compressed-air generating means should liquid flow back from the air bubble generating mat through the air hose length to the air distributor head.

5. An appliance according to claim 1, wherein the connector for joining the length of air hose from the compressed-air generating means to the length of air hose to the air distributor head of the air bubble generating mat is a straight tubular member divided into two halves substantially in the middle, said halves being connected by means of a hinge and their edges having sealingprofiles which form a sealing jointwhen the connector is in position for the passage therethrough of air from the compressed-air generating means.

6. An appliance according to claim 1, wherein the perforated air tubes traversing the air bubble generating mat have different capacities and air outlet holes of different sizes and are connected to the air distributor head which is adapted to control the admission of air into selected perforated air tubes in such a way that the delivered volumes of air can be discharged without the generation of static back pressure.

7. An appliance according to claim 6, wherein a connection for the length of air hose from the connector is provided at one end of the air distributor head which extends substantially across the full width of the air bubble generating mat which on its surface for support- 7 ing the body is provided with transverse grooves.

8. An appliance according to claim 7, wherein the air distributor head consists of a bank of three or more pipes which are closed at each end by a cap common to them all, one of said caps being formed with a connection for the length of air hose to the air distributor head and also containing a rotary disc valve operable from the outside for selectably admitting air into some of smaller-diameter air tubes or alternatively for admitting air into a larger-diameter air tube in the center of the air bubble generating mat and into the directly neighbouring smaller-diameter air tubes of the air bubble generating mat.

9. An appliance according to claim 8, wherein the two caps closing the ends of the air distributor head are interchangeable without affecting the air distributing function.

10. An appliance according to claim 6, wherein the air distributor head consists of a pipe which is closed at both ends, and which movably in a manner providing an airtight sliding seal contains an inner tube rotatably by an external knob, said inner tube being provided with a plurality of, say four, ports for admitting air into paired perforated air tubes on each longitudinal side of the air bubble generating mat, whereas rotation of the inner tube through an angle of say 180 brings a plurality of other ports, say three, into register with outlets leading into an inner larger-diameter perforated air tube and into two smaller-diameter air tubes located directly adjacent the inner larger-diameter perforated air tube on each side thereof.

11. An appliance according to claim 6, wherein the air bubble generating mat in addition to the perforated air tubes having holes in the upper surface of the air bubble generating mat also contains perforated air tubes extending along its two longitudinal edges, the holes in these latter air tubes pointing towards the bottom of a bath tub and being located below the general plane containing the holes of the other perforated air tubes so that appropriate control by the air distributor head will permit a foam bath to be generated when the water level is a minimum. 

1. An appliance for bubbling compressed air through a liquid, particularly water in a bathing tub and the like, comprising compressed-air generating means for blowing compressed air into a controllable air bubble generating mat immersed in the liquid through an air hose incorporating means for preventing liquid from flowing back into the compressed air generating means, said appliance being characterized by the combination of the following features: i. the compressed-air generating means are contained in a synthetic plastics casing which completely encloses the same, contains control means and has an opening closable by a hinged insulating cover; ii. the air hose leads from the compressed-air generating means in the synthetic plastics casing to an air distributor head of the air bubble generating mat and comprises two sEparate lengths of hose joined together by a connector which is airtight only when located at a given level above the air bubble generating mat, and iii. the air bubble generating mat comprises several longitudinally joined caterpillar-like elements and is traversed in its lengthwise direction by a plurality of perforated air tubes connected to the air distributor head which permits compressed air permanently to be selectably admitted into said perforated air tubes.
 2. An appliance according to claim 1, wherein the control means contained in the synthetic plastics casing comprise an electric time switch, an electronic speed regulator or a speed selector switch, a warning lamp and an electrical push button on-off switch for the compressed-air generating means which are all mounted on a common control panel in the plastics casing accommodating the compressed-air generating means in such a way that the push button on the on-off switch is located in the path of deflection of the insulating cover hingeably attached to the edge of the opening, which is nearest to the air hose, said opening given access to said control panel.
 3. An appliance according to claim 1, wherein the connector for joining together the free ends of the air hose length from the compressed-air generating means in the plastics casing and of the air hose length to the air distributor head of the air bubble generating mat is deflectably mounted on a pivot pin on a wall fitting, the portion of said connector cooperating with the air hose length to the air distributor head containing an orifice which during operation of the appliance is sealed by the entry into said orifice of a taper pin attached to the wall fitting.
 4. An appliance according to claim 3, wherein the connector has an enlargement in the region of said orifice and inside said enlargement contains a light-weight ball-shaped float which closes the end of the air hose length from the compressed-air generating means should liquid flow back from the air bubble generating mat through the air hose length to the air distributor head.
 5. An appliance according to claim 1, wherein the connector for joining the length of air hose from the compressed-air generating means to the length of air hose to the air distributor head of the air bubble generating mat is a straight tubular member divided into two halves substantially in the middle, said halves being connected by means of a hinge and their edges having sealing profiles which form a sealing joint when the connector is in position for the passage therethrough of air from the compressed-air generating means.
 6. An appliance according to claim 1, wherein the perforated air tubes traversing the air bubble generating mat have different capacities and air outlet holes of different sizes and are connected to the air distributor head which is adapted to control the admission of air into selected perforated air tubes in such a way that the delivered volumes of air can be discharged without the generation of static back pressure.
 7. An appliance according to claim 6, wherein a connection for the length of air hose from the connector is provided at one end of the air distributor head which extends substantially across the full width of the air bubble generating mat which on its surface for supporting the body is provided with transverse grooves.
 8. An appliance according to claim 7, wherein the air distributor head consists of a bank of three or more pipes which are closed at each end by a cap common to them all, one of said caps being formed with a connection for the length of air hose to the air distributor head and also containing a rotary disc valve operable from the outside for selectably admitting air into some of smaller-diameter air tubes or alternatively for admitting air into a larger-diameter air tube in the center of the air bubble generating mat and into the directly neighbouring smaller-diameter air tubes of the air bubble generating mat.
 9. An appliance according to claim 8, wHerein the two caps closing the ends of the air distributor head are interchangeable without affecting the air distributing function.
 10. An appliance according to claim 6, wherein the air distributor head consists of a pipe which is closed at both ends, and which movably in a manner providing an airtight sliding seal contains an inner tube rotatably by an external knob, said inner tube being provided with a plurality of, say four, ports for admitting air into paired perforated air tubes on each longitudinal side of the air bubble generating mat, whereas rotation of the inner tube through an angle of say 180* brings a plurality of other ports, say three, into register with outlets leading into an inner larger-diameter perforated air tube and into two smaller-diameter air tubes located directly adjacent the inner larger-diameter perforated air tube on each side thereof.
 11. An appliance according to claim 6, wherein the air bubble generating mat in addition to the perforated air tubes having holes in the upper surface of the air bubble generating mat also contains perforated air tubes extending along its two longitudinal edges, the holes in these latter air tubes pointing towards the bottom of a bath tub and being located below the general plane containing the holes of the other perforated air tubes so that appropriate control by the air distributor head will permit a foam bath to be generated when the water level is a minimum. 